Utility of measuring Exhaled Carbon Monoxide (ECO) level in addition to Pulmonary Function Test (Spirometry) in the monitoring of Chronic Obstructive Pulmonary Disease (COPD).

ABSTRACT

Background: The measurement of ECO may represent a new method for the non-invasive monitoring of airway inflammation and oxidant stress in Chronic Obstructive Pulmonary Disease, asthma, bronchiectasis, cystic fibrosis patients. Quantification of lung oxidative stress in stable COPD patients by measuring ECO levels may also contribute to the understanding of the pathophysiology of COPD. Aims & Objective: To study the utility of measuring Exhaled Carbon Monoxide (ECO) level in addition to Pulmonary Function Test (Spirometry) in the monitoring of Chronic Obstructive Pulmonary Disease (COPD). Materials and Methods: COPD patients who were smokers and with a history of exposure to wood smoke (n =60) and healthy non-smokers as control (n =40) were selected as subjects by fulfilling the exclusion criteria as per the GOLD guidelines. Clinical examinations and spirometry including reversibility test were made following the standard protocol/procedure. ECO was measured using a MICRO III Smokerlyser. Results: The difference in level of ECO between COPD cases and healthy non-smokers was highly significant (F = 23.897; df = 98; p < 0.0001). The difference in the level of ECO among different groups (mild, moderate, severe and very severe) was highly significant (F=15.995; df =2; p<0.0001). ECO level in female COPD cases who were exposed to wood smoke was elevated (4.11 ± 1.323) when compared to healthy female non-smokers (1.50 ± 0.519) and the difference was highly significant. (F =1.593; df = 30; p < 0.0001). Conclusion: ECO levels in COPD cases vary with different grades of air way obstruction. We concluded that measuring the level of ECO in COPD cases along with spirometry forms a new approach for better understanding of pathophysiology of COPD cases, with indirect assessment of airway inflammation, oxidative stress and severity of airway obstruction.